The Origins of Scientific Thinking? - York University...1 SC/NATS 1730, IV 1 Greece SC/NATS 1730, IV...

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SC/NATS 1730, IVSC/NATS 1730, IV11

GreeceGreece


The Origins of Scientific Thinking?The Origins of Scientific Thinking?

Greece is often cited as the place where Greece is often cited as the place where the first inklings of modern scientific the first inklings of modern scientific thinking took place.thinking took place.Why there and not elsewhere?Why there and not elsewhere?EinsteinEinstein’’s answer:s answer:

““The astonishing thing is that these The astonishing thing is that these discoveries [the bases of science] were made discoveries [the bases of science] were made at all.at all.””


The Origins of Ancient GreeceThe Origins of Ancient Greece

What we What we call ancient call ancient Greece Greece might better might better be called be called the ancient the ancient Aegean Aegean Civilizations.Civilizations.

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The Aegean CivilizationsThe Aegean Civilizations

There have been civilizations in the There have been civilizations in the Aegean area almost as long as there have Aegean area almost as long as there have been in Mesopotamia and Egypt.been in Mesopotamia and Egypt.The earliest known in the area was the The earliest known in the area was the Minoan Civilization on the island of Crete.Minoan Civilization on the island of Crete.

Existed from about 3000 Existed from about 3000 –– 1450 BCE.1450 BCE.Had some kind of written language, never Had some kind of written language, never deciphered.deciphered.Collapsed suddenly for unknown reasons.Collapsed suddenly for unknown reasons.


The Mycenaean CivilizationThe Mycenaean Civilization

On the Peloponnesus (the southern On the Peloponnesus (the southern mainland) another civilization arose and mainland) another civilization arose and flourished from about 1600flourished from about 1600--1200 BCE.1200 BCE.The The MycenaeansMycenaeans adapted the Minoan adapted the Minoan writing system to their own language, writing system to their own language, Greek. But it was awkward to use.Greek. But it was awkward to use.


MycenaeaMycenaeaThe peak of The peak of the Mycenaean the Mycenaean civilization was civilization was the reign of the reign of Agamemnon, Agamemnon, who took his who took his people (the people (the ““GreeksGreeks””) to ) to war against war against the Trojans.the Trojans.

Agamemnon’s Palace

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The Trojan WarThe Trojan War


The Trojan WarThe Trojan War

Approx. 1280 Approx. 1280 –– 1180 BCE.1180 BCE.MycenaeaMycenaea versus Troy.versus Troy.Won by the Greeks, but the war depleted Won by the Greeks, but the war depleted their fighting forces.their fighting forces.MycenaeaMycenaea was invaded by was invaded by DoriansDorians about about 1200 BCE, and its culture destroyed.1200 BCE, and its culture destroyed.


The Dark Age of GreeceThe Dark Age of Greece

1200 1200 –– 800 BCE800 BCEThe organized Greek civilization was The organized Greek civilization was destroyed by the invading destroyed by the invading DoriansDorians..Knowledge of writing was lost.Knowledge of writing was lost.People lived in isolated villages.People lived in isolated villages.What they had in common was spoken What they had in common was spoken Greek and memories of past greatness.Greek and memories of past greatness.

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PhoeniciaPhoenicia

Around 1700 BCE, in the Near East, what Around 1700 BCE, in the Near East, what is now Lebanon, a civilization developed is now Lebanon, a civilization developed with both Mesopotamian and Egyptian with both Mesopotamian and Egyptian influences.influences.The Greeks later called the people from The Greeks later called the people from there there ““PhoneciansPhonecians”” –– meaning traders in meaning traders in purple.purple.


Phoenician WritingPhoenician Writing

Phoenicians developed a style of writing Phoenicians developed a style of writing that combined Mesopotamian cuneiform that combined Mesopotamian cuneiform and Egyptian and Egyptian heiraticheiratic..It had 22 distinct characters, each It had 22 distinct characters, each representing a particular sound (a representing a particular sound (a consonant).consonant).


The Phoenician AlphabetThe Phoenician Alphabet

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The Phoenician Alphabetic was The Phoenician Alphabetic was PhoneticPhonetic

Since each character represented a sound, Since each character represented a sound, rather than a meaning, the characters rather than a meaning, the characters could be used to represent words in an could be used to represent words in an entirely different language.entirely different language.The Greeks adapted the Phoenician script The Greeks adapted the Phoenician script to their own language and produced an to their own language and produced an alphabetalphabet..


The Homeric AgeThe Homeric Age800 800 –– 600 BCE600 BCEThe Greek verbal culture could be written The Greek verbal culture could be written down.down.The heroic stories of the Trojan WarThe heroic stories of the Trojan Warwere written by Homer.were written by Homer.

The Iliad, The OdysseyThe Iliad, The OdysseyGreek mythology and folk knowledge Greek mythology and folk knowledge were recorded by were recorded by HesiodHesiod..

TheogonyTheogony, Works and Days, Works and Days


The Greek Civilization Takes OffThe Greek Civilization Takes Off

The first Olympic Games 776 BCEThe first Olympic Games 776 BCEThe Polis (CityThe Polis (City--State)State)

Independent governments arose all across the Independent governments arose all across the Greek settlements.Greek settlements.Experimentation in forms of government:Experimentation in forms of government:

Monarchies, Aristocracies, Dictatorships, Monarchies, Aristocracies, Dictatorships, Oligarchies, DemocraciesOligarchies, Democracies

Independent units, but tied together by a Independent units, but tied together by a common language, religion, and literature.common language, religion, and literature.

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Assertion: Scientific Thinking Assertion: Scientific Thinking Began in Ancient GreeceBegan in Ancient Greece

Possible explanations given:Possible explanations given:

ReligionReligion –– The Greek gods were too humanThe Greek gods were too human--like. like.

LanguageLanguage –– Phonetic alphabet encouraged literacy.Phonetic alphabet encouraged literacy.

TradeTrade –– The Greeks became traders and The Greeks became traders and travellerstravellers, , bringing home new ideas.bringing home new ideas.

DemocracyDemocracy –– Democratic governments, where they Democratic governments, where they existed, encouraged independent thought.existed, encouraged independent thought.

SlaverySlavery –– Greeks (like many other cultures) had slaves Greeks (like many other cultures) had slaves who did the menial work.who did the menial work.


The PreThe Pre--SocraticsSocratics

Thinkers living between about 600 Thinkers living between about 600 –– 450 450 BCE.BCE.So named because they (basically) So named because they (basically) predated Socrates.predated Socrates.Known only through discussions of their Known only through discussions of their thoughts in later works.thoughts in later works.Some fragments still exist.Some fragments still exist.


SocratesSocrates

Lived in Athens, 470Lived in Athens, 470--399 BCE.399 BCE.Set the direction of Western Set the direction of Western philosophical thinking.philosophical thinking.The goal of philosophy The goal of philosophy –– to discover the truth.to discover the truth.Reasoning, the supreme Reasoning, the supreme method.method.

Pursued by asking questions, the dialectical, or Pursued by asking questions, the dialectical, or ““SocraticSocratic”” method.method.

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Socrates, contd.Socrates, contd.

Socrates left no writings at all.Socrates left no writings at all.He is known to us primarily through the He is known to us primarily through the works of Plato.works of Plato.

It is hard to distinguish SocratesIt is hard to distinguish Socrates’’ own thought own thought from Platofrom Plato’’s.s.

Socrates is an important figure in the Socrates is an important figure in the development of scientific reasoning, butdevelopment of scientific reasoning, but……He had no interest in the natural world.He had no interest in the natural world.


Back to the PreBack to the Pre--SocraticsSocraticsMost PreMost Pre--Socratics came Socratics came from the Greek from the Greek colonies on the colonies on the eastern side of eastern side of the Aegean Sea the Aegean Sea known as Ionia.known as Ionia.

This is now part This is now part of Turkey.of Turkey.


Wondering about NatureWondering about Nature

The importance of the PreThe importance of the Pre--Socratics is that Socratics is that they appear to be the first people we they appear to be the first people we know of who asked fundamental questions know of who asked fundamental questions about nature, such as about nature, such as ““What is the world What is the world made of?made of?””

And then they provided reasons to justify And then they provided reasons to justify their answers.their answers.

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ThalesThales of of MiletosMiletos625625--545 BCE545 BCEPhoenician parents?Phoenician parents?Stories:Stories:

Predicted solar eclipse of Predicted solar eclipse of May 28, 585 BCEMay 28, 585 BCEFalling into a wellFalling into a wellOlive pressOlive press

WaterWater is the basic stuff of is the basic stuff of the world.the world.


ThalesThales and Mathematicsand Mathematics

ThalesThales is said to have is said to have brought Egyptian brought Egyptian mathematics to Greeks. mathematics to Greeks. Examples:Examples:

All triangles constructed on All triangles constructed on the diameter of a circle are the diameter of a circle are right triangles.right triangles.The base angles of isosceles The base angles of isosceles triangles are equal.triangles are equal.If two straight lines intersect, If two straight lines intersect, opposite angles are equal.opposite angles are equal.


Measuring the distance of a ship Measuring the distance of a ship from shorefrom shore

From the desired point on the From the desired point on the shore, A, walk off a known shore, A, walk off a known distance to point C, at a right distance to point C, at a right angle from the ship and place a angle from the ship and place a marker there.marker there.Continue walking the same Continue walking the same distance again to B.distance again to B.At B, turn at a right angle away At B, turn at a right angle away from the shore and walk until from the shore and walk until the marker at C and the ship are the marker at C and the ship are in a straight line. Call that Ain a straight line. Call that A’’..The distance from AThe distance from A’’ to B is the to B is the same as the distance from A to same as the distance from A to the ship.the ship.

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AnaximanderAnaximander of of MiletosMiletos

611611--547 BCE547 BCEStudent of Student of ThalesThales??Map of the known Map of the known worldworldApeironApeiron (the (the Boundless)Boundless)

The basic stuff of the The basic stuff of the worldworld


AnaximenesAnaximenes of of MiletosMiletos550550--475 BCE475 BCEStudent of Student of AnaximanderAnaximander??AirAir –– the fundamental the fundamental stuffstuffCosmological view:Cosmological view:

Crystalline sphere of the Crystalline sphere of the fixed starsfixed starsEarth in centre, planets Earth in centre, planets betweenbetween


HeraclitosHeraclitos of Ephesusof Ephesus

Ephesus is 50 km N of Ephesus is 50 km N of MiletosMiletos..550?550?--475? BCE (i.e., 475? BCE (i.e., about the same as about the same as AnaximenesAnaximenes, but , but uncertain)uncertain)Everything is Flux.Everything is Flux.

Fire fundamentalFire fundamental"You can't step in the "You can't step in the same river twice."same river twice."

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EleaElea

The minor PreThe minor Pre--Socratic, Socratic, XenophanesXenophanes, fled from , fled from Colophon in Ionia to Colophon in Ionia to EleaElea to escape to escape persecution.persecution.

EleaElea was a was a Greek Greek colony in colony in southern southern Italy.Italy.


Parmenides of Parmenides of EleaElea510510--????Student of the exiled Student of the exiled XenophanesXenophanesThe goal of philosophy is The goal of philosophy is to attain the truth.to attain the truth.The path to truth is via The path to truth is via reason and logic.reason and logic.Reason will distinguish Reason will distinguish appearance from reality.appearance from reality.

Nature is comprehensible Nature is comprehensible and logical.and logical.


Parmenides and the Law of Parmenides and the Law of ContradictionContradiction

Something either Something either isis or it or it is not.is not.

The law of the excluded middleThe law of the excluded middle

Therefore, nothing Therefore, nothing is is that that isnisn’’t!t!

It is impossible to be It is impossible to be not beingnot being

There is no such thing as There is no such thing as emptyempty space.space.

SpaceSpace is something and is something and emptyempty is nothing.is nothing.

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Parmenides against Parmenides against HeraclitosHeraclitos

If there is no space that is empty, the If there is no space that is empty, the

universe is everywhere full and occupied.universe is everywhere full and occupied.

Therefore nothing actually changes.Therefore nothing actually changes.

Therefore motion is impossible.Therefore motion is impossible.


The Fundamental Problem of The Fundamental Problem of ViewpointViewpoint

Focus on the whole Focus on the whole –– ParmenidesParmenidesEasier to grasp the unity of the world.Easier to grasp the unity of the world.Difficult to explain processes, events, Difficult to explain processes, events, changes.changes.

Focus on the parts Focus on the parts –– HeraclitosHeraclitosEasier to explain changes as rearrangements Easier to explain changes as rearrangements of the parts.of the parts.Difficult to make sense of all that is.Difficult to make sense of all that is.


The Perils of LogicThe Perils of Logic

Reasoning with logic inevitably begins with Reasoning with logic inevitably begins with assumed premises, which may or may not assumed premises, which may or may not be true.be true.The reasoning itself may or may not be The reasoning itself may or may not be valid valid –– though this can be checked.though this can be checked.The truth of conclusions depends on the The truth of conclusions depends on the truth of the premises and the validity of truth of the premises and the validity of the argument.the argument.

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Zeno of Zeno of EleaElea

495495--425 BCE425 BCEStudent of ParmenidesStudent of ParmenidesProbably moved to Probably moved to Athens later and taught Athens later and taught there, making his and there, making his and ParmediesParmedies’’ views better views better known.known.


ZenoZeno’’s Paradoxess Paradoxes

Paradox, from the Greek meaning Paradox, from the Greek meaning ““contrary to opinion.contrary to opinion.””Showed that logic can lead to conclusions Showed that logic can lead to conclusions which defy common sense.which defy common sense.

Hard to say whether he was attacking Hard to say whether he was attacking common sense beliefs (as seems probable), common sense beliefs (as seems probable), or demonstrating the dangers of reasoning by or demonstrating the dangers of reasoning by logical deduction.logical deduction.


The StadiumThe StadiumConsider a Consider a stadiumstadium——a running a running track of track of about 180 about 180 meters in meters in ancient ancient Greece.Greece.

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The StadiumThe Stadium

Will the runner reach the other side of the Will the runner reach the other side of the stadium?stadium?


The Stadium ParadoxThe Stadium Paradox

Before the runner can reach the finish line, the midBefore the runner can reach the finish line, the mid--point point must be reached.must be reached.Before that, the Before that, the ¼¼ point. Before that 1/8, 1/16, 1/32, point. Before that 1/8, 1/16, 1/32, 1/64,1/64,…… and an infinite number of prior events.and an infinite number of prior events.The runner never can leave the starting block.The runner never can leave the starting block.


Achilles and the TortoiseAchilles and the Tortoise

Achilles, the mythical speedy warrior, is to have Achilles, the mythical speedy warrior, is to have a footrace with a tortoise.a footrace with a tortoise.Achilles gives the tortoise a head start.Achilles gives the tortoise a head start.

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Achilles and the Tortoise, 2Achilles and the Tortoise, 2

Call the starting time t=0.Call the starting time t=0.Before Achilles can pass the tortoise, he must Before Achilles can pass the tortoise, he must reach where the tortoise was at the start.reach where the tortoise was at the start.Call when Achilles reaches the tortoiseCall when Achilles reaches the tortoise’’s starting s starting position t=1position t=1By then, the tortoise has gone ahead.By then, the tortoise has gone ahead.



Now at time t=1, Achilles still must reach where the Now at time t=1, Achilles still must reach where the tortoise is before he can pass it.tortoise is before he can pass it.Every time Achilles reaches where the tortoise had been, Every time Achilles reaches where the tortoise had been, the tortoise is further ahead.the tortoise is further ahead.The tortoise must win the race.The tortoise must win the race.



An animated demonstration of the paradox.An animated demonstration of the paradox.

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The Flying ArrowThe Flying Arrow

Imagine an arrow in flight. Is it moving?Imagine an arrow in flight. Is it moving?Motion means moving from place to place. Motion means moving from place to place. At any single moment, the arrow is in a single At any single moment, the arrow is in a single place, therefore, not moving.place, therefore, not moving.

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The Flying Arrow, 2The Flying Arrow, 2

At every moment of its flight, the arrow is not At every moment of its flight, the arrow is not moving. If it were, it would occupy more space moving. If it were, it would occupy more space that it does, which is impossible.that it does, which is impossible.There is no such thing as motion.There is no such thing as motion.

The Origins of Scientific Thinking? - York University...1 SC/NATS 1730, IV 1 Greece SC/NATS 1730, IV...

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